// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SERVICES_TRACING_PERFETTO_PERFETTO_SERVICE_H_
#define SERVICES_TRACING_PERFETTO_PERFETTO_SERVICE_H_

#include <memory>
#include <set>

#include "base/macros.h"
#include "mojo/public/cpp/bindings/binding_set.h"
#include "mojo/public/cpp/bindings/strong_binding_set.h"
#include "services/service_manager/public/cpp/identity.h"
#include "services/tracing/public/cpp/perfetto/task_runner.h"
#include "services/tracing/public/mojom/perfetto_service.mojom.h"

namespace perfetto {
class TracingService;
}  // namespace perfetto

namespace tracing {

class ConsumerHost;

// This class serves two purposes: It wraps the use of the system-wide
// perfetto::TracingService instance, and serves as the main Mojo interface for
// connecting per-process ProducerClient with corresponding service-side
// ProducerHost.
class PerfettoService : public mojom::PerfettoService {
 public:
  explicit PerfettoService(scoped_refptr<base::SequencedTaskRunner>
                               task_runner_for_testing = nullptr);
  ~PerfettoService() override;

  static PerfettoService* GetInstance();

  void BindRequest(mojom::PerfettoServiceRequest request, uint32_t pid);

  // mojom::PerfettoService implementation.
  void ConnectToProducerHost(mojom::ProducerClientPtr producer_client,
                             mojom::ProducerHostRequest producer_host) override;

  perfetto::TracingService* GetService() const;

  // Called when a ConsumerHost is created/destroyed (i.e. when a consumer
  // connects/disconnects).
  void RegisterConsumerHost(ConsumerHost* consumer_host);
  void UnregisterConsumerHost(ConsumerHost* consumer_host);

  // Called by TracingService to notify the perfetto service of the PIDs of
  // actively running services (whenever a service starts or stops).
  void AddActiveServicePid(base::ProcessId pid);
  void RemoveActiveServicePid(base::ProcessId pid);
  void SetActiveServicePidsInitialized();

  std::set<base::ProcessId> active_service_pids() const {
    return active_service_pids_;
  }

  bool active_service_pids_initialized() const {
    return active_service_pids_initialized_;
  }

 private:
  void BindOnSequence(mojom::PerfettoServiceRequest request);
  void CreateServiceOnSequence();

  PerfettoTaskRunner perfetto_task_runner_;
  std::unique_ptr<perfetto::TracingService> service_;
  mojo::BindingSet<mojom::PerfettoService, uint32_t> bindings_;
  mojo::StrongBindingSet<mojom::ProducerHost> producer_bindings_;
  std::set<ConsumerHost*> consumer_hosts_;  // Not owned.
  std::set<base::ProcessId> active_service_pids_;
  bool active_service_pids_initialized_ = false;

  DISALLOW_COPY_AND_ASSIGN(PerfettoService);
};

}  // namespace tracing

#endif  // SERVICES_TRACING_PERFETTO_PERFETTO_SERVICE_H_